NAME
String::Similarity - calculate the similarity of two strings
SYNOPSIS
use String::Similarity;
$similarity = similarity $string1, $string2;
$similarity = similarity $string1, $string2, $limit;
DESCRIPTION
$factor = similarity $string1, $string2, [$limit]
The "similarity"-function calculates the similarity index of its two
arguments. A value of 0 means that the strings are entirely
different. A value of 1 means that the strings are identical.
Everything else lies between 0 and 1 and describes the amount of
similarity between the strings.
It roughly works by looking at the smallest number of edits to
change one string into the other.
You can add an optional argument $limit (default 0) that gives the
minimum similarity the two strings must satisfy. "similarity" stops
analyzing the string as soon as the result drops below the given
limit, in which case the result will be invalid but lower than the
given $limit. You can use this to speed up the common case of
searching for the most similar string from a set by specifing the
maximum similarity found so far.
SEE ALSO
The basic algorithm is described in:
"An O(ND) Difference Algorithm and its Variations", Eugene Myers,
Algorithmica Vol. 1 No. 2, 1986, pp. 251-266;
see especially section 4.2, which describes the variation used below.
The basic algorithm was independently discovered as described in:
"Algorithms for Approximate String Matching", E. Ukkonen,
Information and Control Vol. 64, 1985, pp. 100-118.
AUTHOR
Marc Lehmann
http://home.schmorp.de/
(the underlying fstrcmp function was taken from gnu diffutils and
modified by Peter Miller and Marc Lehmann
).